1. Field of the Invention
The present invention relates to a key actuating apparatus and a key actuation control system.
Priority is claimed on Japanese Patent Application No. 2006-241791, filed Sep. 6, 2006, the content of which is incorporated herein by reference.
2. Description of Related Art
In general, a natural keyboard musical instrument such as an acoustic piano has a constitution in which, for example, a natural sound is generated by hitting a string with a rotatably movable hammer when a key is pushed. Such the natural keyboard musical instrument has an action mechanism between the key and the hammer. The action mechanism affects a special reacting force (braking force of the key) on a player via the key. In other words, the natural keyboard musical instrument has its own touch of the key.
On the other hand, a conventional electric keyboard musical instrument such as an electric keyboard which generates an electric sound has a spring for returning the key to an initial position. The conventional electric keyboard musical instrument has a constitution in which, the player operates the key while acting against the reacting force of the spring upon pushing the key. Therefore, the resistance of the key of the electric keyboard musical instrument is obtained by using a simple returning force of the spring and is greatly different from the resistance of the key of the natural keyboard musical instrument.
There is prior art (for example, Patent Document 1 (Japanese Unexamined Patent Application, First Publication No. H04-204697) and Patent Document 2 (Japanese Examined Patent Application, Second Publication No. H07-111631)) which have an object to obtain the same resistance of the key as the natural keyboard musical instrument with the action mechanism even by using the electric keyboard musical instrument. In the prior art, a key actuating apparatus which applies a reacting force against a pushing force on the key by actuating the key is proposed. In the prior arts, a key actuating apparatus which is an electromagnetic actuator of a solenoid type is used. Other than a function of applying the reacting force, the keyboard musical instrument of the prior art has a function of autonomous playing in which keys are operated by the key actuating apparatus in accordance with operation information corresponding to a set of sounds constituting music.
In the Patent Documents 1 and 2, the key actuating apparatus has the electromagnetic actuator of the solenoid type. Therefore, there is a problem in which the key actuating apparatus is large and heavy. This problem is especially critical because the electric keyboard musical instrument such as an electric keyboard has a great demand with regard to portability.